Log-Linear Analog Output - Instrutech CVM211 User Manual

Instruction Manual
7.2

Log-Linear Analog Output

The following table is for use with CVM211 Stinger part numbers ending with the letter "L" providing an output
voltage that is linear with respect to the log of pressure.
Log-Linear analog output for CVM211GAA-B-L through CVM211GHA-B-L
True
Pressure
(mbar) N
2
0.0001 1.000 1.000
0.0002 1.301 1.301
0.0005 1.699 1.699
0.0010 2.000 1.903
0.0020 2.301 2.146
0.0050 2.699 2.524
0.0100 3.000 2.820
0.0200 3.301 3.188
0.0500 3.699 3.512
0.1000 4.000 3.809
0.2000 4.301 4.103
0.5000 4.699 4.495
1.0000 5.000 4.784
2.0000 5.301 5.064
5.0000 5.699 5.404
10.0000 6.000 5.633
20.0000 6.301 5.815
50.0000 6.699 5.969
100.0000 7.000 6.045
200.0000 7.301 6.093
300.0000 7.477 6.131
400.0000 7.602 6.178
500.0000 7.699 6.237
600.0000 7.778 6.295
700.0000 7.845 6.349
760.0000 7.881 6.380
800.0000 7.903 6.399
900.0000 7.954 6.488
1000.0000 8.000 6.494
1100.0000 8.041 6.539
1200.0000 8.079 6.580
1300.0000 8.114 6.624
1333.0000 8.125 6.636
The log-linear output signal and pressure are related by the following formulas:
P = 10
where P is the pressure in mbar, and V is the output signal in Volts.
An analog output of less than 0.01 volts to near 0 volt indicates a damaged or faulty sensor.
The chart on the following page shows the graphical results of the table and formulas given above for nitrogen.
True pressure (N ) is plotted on the X-axis with a log scale. The output signal is plotted on the Y-axis on a linear
2
scale.
InstruTech
Ar He O
2
1.000 1.000
1.301 1.301
1.699 1.699
1.938 2.000
2.204 2.301
2.602 2.699
2.908 2.991
3.208 3.294
3.607 3.693
3.928 3.989
4.217 4.288
4.634 4.686
4.962 4.987
5.324 5.288
6.070 5.695
8.125 6.008
8.125 6.337
8.125 6.862
8.125 7.282
8.125 7.526
8.125 7.625
8.125 7.705
8.125 7.786
8.125 7.861
8.125 7.928
8.125 7.965
8.125 7.988
8.125 8.042
8.125 8.092
8.125 8.125
8.125 8.125
8.125 8.125
8.125 8.125
Values listed under each gas type are in volts.
(V - 5)
V = log (P) + 5
10
CO KR Freon12
2
1.000 1.000 1.000
1.301 1.301 1.301
1.699 1.523 1.699
2.028 1.668 2.125
2.355 1.970 2.487
2.672 2.370 2.883
3.012 2.675 3.172
3.345 2.979 3.473
3.741 3.372 3.863
4.033 3.671 4.157
4.325 3.963 4.445
4.696 4.341 4.798
4.982 4.614 5.044
5.249 4.865 5.250
5.550 5.141 5.447
5.743 5.309 5.556
5.886 5.433 5.621
6.002 5.514 5.680
6.065 5.548 5.751
6.157 5.606 5.851
6.253 5.654 5.918
6.353 5.679 5.962
6.448 5.710 5.996
6.532 5.734 6.025
6.611 5.754 6.050
6.658 5.765 6.063
6.687 5.772 6.072
6.766 5.787 6.092
6.847 5.799 6.111
6.936 5.812 6.128
7.028 5.822 6.146
7.140 5.828 6.164
7.169 5.830 6.169
CVM211 Stinger
Freon22 D Ne
2
1.000 1.000 1.000
1.301 1.301 1.301
1.699 1.699 1.699
2.125 2.080 1.903
2.487 2.392 2.166
2.855 2.778 2.551
3.136 3.082 2.849
3.434 3.385 3.150
3.837 3.779 3.543
4.136 4.082 3.844
4.424 4.393 4.148
4.783 4.828 4.553
5.037 5.174 4.867
5.255 5.579 5.192
5.471 7.288 5.696
5.602 8.125 6.252
5.675 8.125 7.608
5.722 8.125 8.125
5.780 8.125 8.125
5.877 8.125 8.125
5.950 8.125 8.125
6.000 8.125 8.125
6.038 8.125 8.125
6.070 8.125 8.125
6.097 8.125 8.125
6.112 8.125 8.125
6.122 8.125 8.125
6.146 8.125 8.125
6.167 8.125 8.125
6.187 8.125 8.125
6.204 8.125 8.125
6.222 8.125 8.125
6.228 8.125 8.125
CH
4
1.000
1.301
1.699
2.167
2.523
2.893
3.186
3.484
3.886
4.197
4.500
4.893
5.201
5.517
5.877
6.374
7.409
7.930
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
8.125
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